1. Field of the Invention
This invention relates to mountaineering equipment and more particularly concerns a shovel and trenching tool blade attachment adapted to be affixed to a climber's ice axe.
Climbing in snow is a fundamental part of mountaineering. Climbers like snow for several reasons. First of all, it makes many climbs a lot easier by providing a pathway over brush and other obstacles on the approach hike and reducing the danger of loose rock on the ascent. It also brings new beauty to the mountains and conceals the impact of people upon the environment.
Snow is a complex medium that shows up in many forms that continually change, making snow travel trickier than trail hiking or rock climbing. Snow falls in a form that varies from tiny crystals to coarse pellets, depending on temperature and wind. Once fallen, snow begins to change as it is acted upon by sun, wind, temperature variations, and precipitation. Even in the course of a day, the snow can change from rock hard in the morning to thigh-sucking slush in the afternoon and back again by evening.
The ice axe is one of the most versatile and important pieces of mountaineering equipment a climber owns. Without it, safe alpine travel is restricted to easy scrambles. With an axe, and the skill to use it, the climber can venture onto all forms of snow and ice, enjoying a greater variety of mountain landscapes during more seasons of the year.
The modern ice axe is an inherently simple tool with many uses. Below the snow line, it's used for balance, as a walking cane, and to help brake going downhill. But its main role is in snow and ice travel, where it provides balance and a point of security or safety to prevent or arrest a fall. It is also used to chop steps in icy snow for foot holds and can be used as a brake for a controlled sliding technique known as glissading. Furthermore, it can become a snow anchor when buried in the snow.
The ice axe has several parts: 1) the head, which includes A) the pick, namely a pointed protrusion, and B) the adze, a curved flat scoop extending opposite the pick, 2) the shaft, a rounded or oval tube of various lengths made of aluminum alloy, titanium or a composite material (fiberglass Kevlar or carbon filament), and 3) the spike, a sharp steel tip on the opposite end of the shaft from the head.
The pick on most ice axes is curved or drooped, a design that provides better hooking action in snow or ice, causing the axe to dig in faster when trying to stop oneself after a fall. A moderate hooking angle of 65 to 70 degrees from the shaft is typical for general mountaineering uses. A sharper angle of 55 to 60 degrees is commonplace for technical ice climbing, as it coincides with the arc followed by the axe head when it is planted in steep ice. Some ice climbing axes permit adjustable bolted pick angles. However, over 90% of the ice axes in use are for snow climbing, and have a moderate hooking angle of 65 to 70 degrees. The head is made of 1/8 to 3/16 steel alloy stamped out before hardening. The adze part of the ice axe is either attached before hardening by welding or simply formed by a quarter turn of the heat-softened head. Any of these designs are suited for the invention now being proposed.
The most critical function of the ice axe is a maneuver referred to as self-arrest. Self-arrest is the lifesaving technique of using the ice axe to stop the climber's uncontrolled or accidental slide down a snow slope. If unroped, it offers the only chance to stop the slide. It's the single most important snow-climbing skill. The technique also serves to brace a climber solidly in the snow if he has to hold the fall of a rope-mate. Therefore, a climber's own life and those of fellow climbers could hinge on self-arrest.
In the self-arrest maneuver, the hands hold the axe in a solid grip, one hand with thumb under the adze and fingers over the pick, the other hand on the shaft just above the spike.
The pick is pressed into the snow just above the climbers shoulder so that the adze is near the angle formed by the neck and shoulder.
The shaft crosses the chest diagonally and is held close to the opposite hip. Gripping the shaft near the end prevents that hand from acting as a pivot around which the spike can swing to jab the thigh. The chest and shoulder are pressed strongly down on the ice-axe shaft. The spine is arched slightly away from the snow. This arch is critical; it places the bulk of the climber's weight on the axe head and on the toes or knees, the points that dig into the snow to force a stop.
A common problem experienced by climbers occurs when a climb is being made along a steep, near vertical surface in soft snow, semi-firm snow or soft crust. If the snow were solidly packed or ice, the climber would simply use the axe in the above manner. However, on this softer type snow the above self-arrest technique does not work. The pick head may be sunk into the snow to its fullest extent and the falling climber continues to accelerate. The narrow pick simply cannot generate enough drag or braking force to slow the person. The adze does not have enough area to provide any significant braking force either. The spike is the only part that can generate enough braking force by being sunk deeply into the snow. However, the only safe way to hold this position is in a sitting glissade position which is not considered a safe self-arrest position.
The book: Mountaineering, Freedom of the Hills, 5th edition (considered the "bible" of mountaineering) contains an illustration on page 289 indicating that rolling toward the spike for self-arrest is incorrect while also stating on that same page under "Variations" that the greatest possible drag from the ice axe on loose snow may be in this position. Thus, a danger does exist by losing control on this position. It is for these types of snow that this invention is proposed. Snow conditions vary from hard ice, where even a very sharp pick has difficulty penetrating, to very loose "powder" where an ice axe may not be needed at all to stop a fall. Actually, mountaineers may encounter both in the course of a winter climb along with all types in between.
Another mountain climbing skill performed with the ice axe is self-belay. It is usually performed on gentle to semi-steep slopes with the spike used like a walking cane for control and an anchor point for a slip. On steep slopes, a climber can make a direct assault by chopping the pick into the snow and pulling with the arms while climbing with the legs. (Commonly known as "climbing on all fours"). The pick serves as the anchor point if the legs slip. Ice climbers use two small ice climbing axes (one in each hand) and crampons on their boots to work their way up a slope "on all fours." Again, this technique does not work on semi-firm snow, soft snow or soft crust, since the narrow pickhead pulls too easily through the snow. This problem is resolved also by this invention.
Two other ice axe functions are enhanced by virtue of the improvement of the present invention. The first is a technique know as glissading. Glissading, as mentioned earlier is a self-controlled slide down a snow slope, most commonly done in a sitting position (which is its most stable and safe position) wherein the spike is dug into the snow for braking purposes. It is an easy and enjoyable way to descend hard to semifirm snowfields which have enough angle to the slope to slide. This invention provides an additional position for soft or semifirm snow wherein the shovel attachment is employed for braking effect.
The second function improved by virtue of the present invention is that wherein the ice axe is used as a snow anchor. Climbers frequently use snow anchors and pickets for attaching ropes to belay. The ice axe can be buried vertically or horizontally (as a "dead man anchor") in the snow for rope attachment. The present invention enables the ice axe to be used as a snow anchor by burying or sinking the entire unit beneath the snow and attaching a rope to the handle.
A broad-bladed shovel is another utility and safety tool for snow travel. It's the only practical tool currently available for uncovering an avalanche victim. Shovels are also used for digging snow shelters and leveling off tent platforms and have been used as a climbing tool to shovel a pathway up a particularly snowy route.
A good snow shovel has a blade large enough to move snow efficiently and a handle long enough for good leverage but short enough for use in a confined area. Some snow shovels come with a detachable handle or with a blade that locks perpendicular to the handle so it can be used as a trenching tool. For projects such as building snow caves, mountaineers sometimes carry a grain scoop, a broad-bladed shovel that can move a lot of snow.
Mountaineers are extremely conscious of the weight and bulk of gear that they carry because it represents added effort and encumbrance in climbing. Therefore, the need to carry an extra shafted tool such as a shovel must be weighed against its encumbrance. There may be no way to rescue an avalanche victim or dig an emergency snow shelter (snow cave) without a shovel. This invention provides a small lightweight solution to this problem.
2. Description of the Prior Art
Numerous shovel adapters have been disclosed in the prior art. Various blades have been employed in attempts to extend the versatility of hammers, picks, scrapers and other tools. For example, U.S. Pat. No. 4,475,756 to Reading discloses a Shovel adapter for a geologist's hammer. The blade has a plurality of slots adapted to receive the pick end of the hammer. It is locked in place with locking hardware. By virtue of the design of the shovel blade and locking hardware, the adapter is not quickly deployed and removed. Furthermore, when not deployed upon the hammer, it must be stored separately. There is no non-deployed storage position for the blade.
U.S. Pat. No. 3,334,939 to Bonic discloses a combination snow shovel and ice scraper in which the shovel blade may be locked into place upon the scraper blade. This mounting disposes the shovel blade in a plane common with, rather than orthogonal to, the shaft of the tool. When not deployed upon the scraper, the shovel blade must be stored separately as well.
Neither of these shovel devices are amenable to use with an ice axe.
It is therefore an object of the present invention to provide a spade attachment for an ice axe which permits the use of the ice axe as a shovel or trenching tool while enhancing its gripping ability in loose snow in self-belaying and self-arresting maneuvers.
It is another object of the present invention to provide a spade attachment of the aforesaid nature which may be quickly and easily deployed and removed.
It is a further object of this invention to provide a spade attachment of the aforesaid nature adaptable to a myriad of commercially available ice axes.
It is yet another object of this invention to provide a spade attachment of the aforesaid nature which may be stored in non-operative association with the ice axe.
It is still another object of this invention to provide a spade attachment of the aforesaid nature which is lightweight, durable, and amenable to low cost manufacture.
It is another object of this invention to make use of the top surface of the spade for printing safety messages for climbers. This is appropriate to its relation to safety (avalanche rescue, emergency snow shelter, self arrest). This may be stamped into the metal or molded if the spade is made of plastic.
These and other beneficial objects and advantages will be apparent from the following description.